Reserpine (Ib) was isolated for the first time in 1952 from Rauwolfia serpentina extracts by Schlitter (Muller et al, Experientia 1952, 8, 338) and identified as the main responsible for the ipotensive activity of Rauwolfia spp extracts.

Deserpidine (Ia) was isolated for the first time in 1955 from Rauwolfia canescens roots by Hofmann (Stoll and Hofmann, J. Am. Chem. Soc. 1955, 77, 820).

Over the years reserpine and related indole alkaloids, such as deserpidine, have played an important role in the treatment of hypertensive, nervous and mental disorders. Even if deserpidine has an interesting pharmacological profile, its use has always been limited compared with reserpine due to its poor availability in nature. In fact, deserpidine titre in the cortical part of the roots is of about 0.003-0.005%, whilst reserpine titre is of about 0.1-0.2%.
Deserpidine is structurally related to reserpine (Ib) and rescinainmine (Ic).

Compared to reserpine, deserpidine lacks the methoxy group at the 11-position. Compared to rescinnamine, deserpidine lacks the methoxy group at the 11-position and is esterified at the 18-position with a 3,4,5-trimethoxybenzoic residue instead of a 3,4,5-trimethoxycinnamic residue.
Theoretically, the conversion of reserpine to deserpidine could be carried out through demethoxylation of the 11-position. According to known organic chemistry methods, the easiest way could be either the direct demethoxylation of reserpine or the conversion of the 11-methoxy group to hydroxy group, followed by reduction of the phenol ring to benzene ring.
It is known to those skilled in the art that the polyfunctionalization of reserpine, rescinnamine and methyl reserpate (Id)
does not allow selective O-demethylation of the hydroxy group at the 11-position. The known methods for direct 11-demethoxyation or 11-O-demethylation lack regioselectivity and/or chemoselectivity.
It has now been found that these problems can be overcome using reserpic acid lactone as the precursor.